Transmission op pictures



June 24, 1930. R, .5, KE 1,768,453

TRANSMISSION OF PICTURES Filed July 25, 1927 Fig. l. k

II /"9b Fre gaency I Gianmzor M 40 M Invenror- Ray D. Kell, B MJQZLZ.

His ATTor-ne g.

Patented June 24, 1930 NITED STATES PATENT OFFICE RAY in. mm, or scorn, NEW YORK, Assrenon '10 GENERAL nnn c rnrc comm, A.

conronarron or NEW 'ZOBK TRANSMISSION OF PICTURES Application filed an 25,

My invention relates to the transmission of pictures, and has for its principal ob ect the provision of an improved, picture receiving apparatus which -may be readily controlled to maintain it in synchronism with the apparatus by which the picture is transmitted.

In the transmission of pictures, it is essential that means be provided for successively scanning the elemental portions of the picture and for producing electrical impulses which are proportional to the intensity or color of the light emitted by these successive portions. It is also essential that means be provided for maintaining synchronism between the moving parts of the transmitting and receiving apparatus. When the picture is to be received by amateurs, it is especially desirable that the receiving apparatus be readily adjusted to operate in synchronism with any transmitting station desired. in accordance with my invention, this result is accomplished by the provision of an improved means for controlling thespeed of the receiving apparatus and indicating the relation between this speed and the speed of the transmitting apparatus.

My invention will be better understood from the following description when considered in connection with the accompanying drawings and its'scope will be pointed out in the appended claims.

eferring trates a picture transmitt ng apparatus; and Fig. 2v illustrates a picture receiving ap- 4 paratus wherein my invention has been embodied.

The transmitting apparatus illustrated by Fig. 1 comprises a rotatable drum 1 upon which the picture to be transmitted is mounted, an oscillation generating and amplifying device 2 of any suitable type, and an antenna 3 to which a hi h frequency carrier current is supplied rom the device 2.

The drum 1 is geared to a driving motor 4: through a gear 5 mounted on the motor shaft 6 and a gear 7 mounted on the drum shaft 8 which is provided with a spline arranged to permit both rotation and endwise movement of the drum. Endwise to the drawings, Fig. 1 illus- 1927. Serial no. 2os,2o1.

movement of the drum 1 is produced by a screw drive 9 which is geared to the motor at through gears 10 and 11. Under these conditions, rotation of the drum is produced by the gears 5 and '2 and endwise movement of the drum is produced by the gears 10 and 11.

fiected from the picture to a light responsive 7 device such as a photo-electric cell 17 or the like. Thus assuming the motor 4: to be operating, the high frequency carrier current supplied to the antenna 3 from the device 2 is modulated both in accordance with the speed of the drum 1 and in accordance with the color of the elemental portions of the picture which is moved endwise so that these portions are successively subjected to the light of the source 15. It will be apparent that any other suitable picture transmitting apparatus may be used instead of that illustrated by Fig 1.

The picture receiving apparatus illustrated by Fig. 2 comprises a radio receiving device 18 which is connected to an antenna 19 and is arranged to separate the modulating impulses produced respectively by the contact-making device of Fig. 1 and by the variation in the intensity of the light reflected from the elemental portions of the picture mounted on the drum 1. The modulating impulses produced by the contact making device are applied to a circuit which comprises a light 20 and a contact making device 21 which is similar to that of Fig. 1. The modulating impulses produced by variation in the color of the picture are applied t9 the operating coil of an oscillograph 22. c,

The picture receiving apparatus of Fig. 2 also comprises a drum 23 splined to a shaft 24 which is coupled to the shaft of a motor 25 through gears 26 and 27 Endwise move-- ment of the drum 23 along the shaft 24 is produced through gears 28 and 29 which are interposed between the shafts of the motor and the drum. A disk 30 provided with an opening 31 is mounted on the motor shaft, and a key 32 is connected in shunt to a resistor 33 through which current is supplied to the field circuit of the motor 25.

In order that the picture mounted on the drum 1 may be reproduced on a light sensitive material mounted on the drum 23, it is essential that synchronism be maintained between the rotational movements of the drums andbetween the endwise movements of the drums. Equality in the speeds of the two drums is produced by the key 32 whichis tapped or vibrated at such a speed as to vary the effect of the resistor 33 and raise or lower the speed of the motor 25 until the light of the lamp 20 is visible.through the opening on the drum. If the speed of the motor 4 is constant, this of course requires that the key'32 be tapped at a substantially constant "speed after the motor 25 has attained a speed corresponding to the motor 4. It has been. found that the speed of the motor 25 may be readily adjusted to and maintained at any desired speed by an operator very slightly skilled in the use of the key. parent that this method of synchronizing the transmitting and receiving apparatus has the advantages that it does not require an expensive receiving apparatus and makes it possible for the ordinary amateur to receive pictures from difl'erent radio transmittin stations. I

he embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention is susceptible of being modified to meet the difl'erent conditions encountered in its use and 1] therefore aim to cover-by the appended claims all modifications within the true spirit and scope of my invention. -Wliat-I claim as new and desire to secure by Letters Patent of the United States,"is:-- 1. A picture receiving apparatus comprising means for receiving and separating a plurality of electrical impulses each having successive maximum and values,

means for driving said apparatus, a mem- It will be 'ap-' ent on the speed of said the variation in the color ber arranged to be manually vibrated for controlling the speed of said driving means, and means for indicating when said driving means is operating at a speed in synchronism with the variations in the magnitude of one of said impulses.

' 2. A' picture receiving apparatus comprismeans for receiving and separating a; plurality of electrical impulseseach having successive maximum and values, means for driving said apparatus, manually operated means for controlling the speed of said driving means, means including a" perforated disk arranged to be rotated by said driving means and a light source controlled by one of said impulses for indicating when said driving means is operated at a speed in synchronism with the variations in the magnitude of said one of said impulses, and 2.

means arranged to produce light of an inother of said impulses.

3. A picture receiving apparatus comprising means for receiving and separating a plurahty of electrical impulses each having successive maximum and minimum values,

means for driving said apparatus, a member tensity which varies in accordance with an- 7 arranged to be manually vibrated for con- I trolling the speed of said driving means, means for indicating when said driving means is operated at a speed in synchronism with the variations in the magnitude of one of saidiinpulses,.means arranged to produce light of an intensity which varies in accord- 'ance with another of said impulses, and

means operated by said driving means for producing a record dependent on the intensity of said light.

4. The combination of a picture transmitting apparatus operable to transmit electrical impulses which are respectively dependent on the speed of said apparatus and on the variation in the color of the successive elemental portions of the picture to be transnitted, and a receiving apparatus comprisng means for receiving and separating said impulses, means for driving said receiving apparatus, a key for controlling the speed of said (ll'lVlIlg means, and means for indi- .cating when said driving means isoperated in synchronism with variations in the magnitude of the impulse dependent on the speed of said transmitting apparatus.

5. The combination of a tingapparatus operable to transmit electrical impulses which are respectively dependapparatus and-on I I of the successive elemental portions of the picture to be transimtted, and a receiving apparatus comprisng means for receiving and impulses, means for driving said apparatus a key for controlling of said driving means, a disk arranged to be rotated by said driving means and proreceiving separating saidpicture transmit- V I vided with an opening, and a light alined with the path of said opening and arranged to be subjected to the impulses dependent on the speed of said transmitting apparatus.

In witness whereof, I have hereunto set my hand this 22nd day of July, 1927.

RAY D. KELL. 

